Music That's in the Zone

Including the amp makes sense if you buy into how Sonos envisions your use of the system. Via the product's analog outputs, you could just hook a single player up to a stereo (and a subwoofer) in your living room or den. But Sonos would like you to place multiple players--up to 32 of them--all over your house. They connect to each other over ethernet or over a proprietary 802.11-based "mesh" network: Each player acts as both a sender and a receiver, with no need for a central hub or router.

The system can play digital music from up to 16 sources--computers or network drives--and every player can have its own line-in source that is broadcast over the network. You can queue different music selections on each player, or put all of them into a "party zone" that plays the music in perfect synchronization (no echo or delay, in my tests). Or you can create multiple such zones in your house. Two ZonePlayers I tested connected flawlessly, despite being separated by about 50 feet and three walls. The system falls short of wireless perfection, however, because at least one player must be linked to your network via an ethernet cable. (Sonos says the mesh nature of the wireless network makes it incompatible with a regular home Wi-Fi network.)

Multitudinous Music

The Sonos system plays .wav, MP3, WMA, and AAC music files (but not copy-protected files such as ones from the Apple ITunes store). Sonos says Microsoft's Plays for Sure protection format doesn't support multiple-room listening, but Rhapsody support is coming in March. The Sonos system plays Internet radio, as well: 64 stations came preprogrammed on the system I tested, and adding more was a cinch, especially via the PC-based control software. Each ZonePlayer also has stereo line-in jacks for receiving analog input--say, from a CD player, a radio, an IPod, or a TV--and broadcasting it around the house.

Sonos claims a one-week battery life for the controller, but in my tests it conked out after three to four days. That's still quite good, however, and the battery charges up in a reasonable 2 hours via an included AC adapter. (Sonos plans to offer a $50 charging cradle in a few months.)

A Few Off Notes

The Sonos system is amazingly polished for a debutante, but it still has flaws. The controller scans the network and associates with the nearest player, but it can be sluggish when switching from one player to the next. And on a few occasions, it lost contact with the entire network; sometimes it recovered after a few minutes, sometimes it required a restart.

The amp is powerful, and music sounded rich going through a set of Klipsch RB-15 speakers that Sonos provided for my evaluation. But after comparing the output of the Sonos amp with that of my own amp (again, using the Klipsch speakers), I thought it was a bit heavy on the bass and weak in treble, giving vocals a slightly distant sound. Tweaking the bass and treble controls didn't have much effect, either. And Sonos doesn't currently provide a multiband equalizer, although the company is considering adding one via a downloadable software update.

Overall, the glitches were not enough to change my very favorable impression of the product. Had I a spare five grand, I would happily put ZonePlayers and speakers in every room of my apartment and spring for a pair of controllers. But all I really need are adapters for the stereo systems in my front and back rooms. So instead of a pricey box with an amp, I'd prefer an entry-level unit with just the line-out ports (in other words, no amplifier). I'm not the only person to make this request, however, and Sonos says it is considering adding such a product to its lineup. I'd also like a USB 2.0 port on the player; network drives are great for some situations, but USB-connected disks are cheaper and far more common.

So, I'm not quite ready to pony up for my own Sonos setup. But I will certainly miss my evaluation system when I ship it back in a few days.